Gracilariaceae subfam.

Gurgel, Carlos Frederico D., Norris, James N., Schmidt, William E., Le, Hau Nhu & Fredericq, Suzanne, 2018, Systematics of the Gracilariales (Rhodophyta) including new subfamilies, tribes, subgenera, and two new genera, Agarophyton gen. nov. and Crassa gen. nov., Phytotaxa 374 (1), pp. 1-23 : 4

Gracilariaceae subfam. Gracilarioideae Stizenberger, 1860: 41, emend.

TYPE: Gracilaria compressa (C. Agardh) Greville 1830: 125 , basionym: Sphaerococcus compressus C. Agardh 1822: 308 ; which is now Gracilaria bursa-pastoris (S.G. Gmelin) P.C. Silva 1952: 265 ; basionym: Fucus bursa-pastoris S.G. Gmelin 1768: 121 , pl. VIII [8]: fig. 3. This is the type species for the genus, subfamily, family, and order.

DIAGNOSIS: Free-living or parasitic. Tetrasporangia either in sori or not associated with any special development of cortical cells; spermatangial parent cells of outer cortical, subcortical and intercalary cell origin, distributed either as conceptacles of different depths and shapes (i.e., cavities within the thallus) or cortical and superficial, without the formation of nemathecia; gonimoblast individual cells often irregular in shape, gonimoblast mass not filling the entire cystocarp cavity; carposporangia formed in short files; transition between gonimoblasts and carposporangia gradual or pronounced at different stages of maturity, mature carposporangia large and conspicuously differentiated from mature gonimoblasts.

GENERA IN SUBFAM. GRACILARIOIDEAE: Agarophyton (herein), Crassa (herein), Gracilaria (including Congracilaria Yamamoto , Gracilariophila Setchell et H.L.Wilson - in part, and Gracilariocolax Weber-van Bosse), Gracilariopsis Dawson (including Gracilariophila in part) and Hydropuntia Montagne.

REMARKS: On the basis of phylogenetic results only, Congracilaria and Gracilariophila should be subsumed into one of three of the genera in the subfam. Gracilarioideae ( Ng et al. 2014, 2015, 2016). The generitype Congracilaria babae H. Yamamoto (1986: 287) was treated as belonging in the genus Gracilaria by Ng et al. (2014, as Gracilaria babae (H. Yamamoto) Ng, P. -K. P.-E.Lim et S.-M. Phang). Ng et al. (2014) also suggested Gracilariocolax Weber-van Bosse (1928) to be congeneric with Gracilaria . Due to their highly modified morphology, we refrain from making a taxonomic opinion on the alloparasite Holmsella Sturch ( Fredericq & Hommersand 1990c) .